Discovery Sheds New Light on Human Evolution
Her remains, unearthed by researchers this past summer, are the subject of a study published in Nature.
Source: Wikimedia
This research reveals new insights into human evolution and the interactions between our ancient relatives.
A Forgotten Branch of Humanity
Homo sapiens are not the only human species to have walked the Earth; until relatively recently, we shared the planet with our evolutionary relatives, the Neanderthals and Denisovans.
Source: Moneycontrol
While Neanderthals are widely known, Denisovans remain relatively obscure. Discovered only in 2010, the Denisovans are still a mystery, with so few fossils that their appearance remains unknown.
A Vanishing Species
It’s believed they disappeared around the same time as the Neanderthals, roughly 40,000 years ago.
Source: Jakub Hałun/Wikimedia Commons
The hybrid human, designated Denisova 11, marks just the fifth Denisovan fossil ever discovered, making her mixed heritage particularly intriguing.
Limited Clues from a Small Fragment
The researchers found only a small bone fragment, which, along with the other Denisovan remains, offers limited insight into these ancient people.
Source: Wikimedia
Yet, we know this girl had parents from two different species and likely lived among both in the cave.
A Genetic Revelation
DNA sequencing of the bone fragment revealed that Denisova 11’s chromosomes were evenly split between Denisovan and Neanderthal origins.
Source: Freepik
Initially, Viviane Slon, a graduate student involved in the study, thought she had made an error.
Confirming the Hybrid Hypothesis
However, when the hybrid hypothesis was proposed, the DNA findings provided “good proof that this was real,” as she explained.
Source: athree23/Wikimedia Commons
By examining mitochondrial DNA, which is inherited exclusively from the mother, researchers determined that Denisova 11’s mother was a Neanderthal and her father was a Denisovan.
Tracing Ancestry and Migration Patterns
Her father’s DNA closely resembled that of the first Denisovan discovered in the same cave, while her mother’s DNA was more similar to Neanderthals who lived in Croatia thousands of years later.
Source: Gizmodo
This suggests there were migrations of Neanderthal populations within the last 100,000 years.
The Growing Evidence of Ancient Interbreeding
In 2015, scientists discovered the 40,000-year-old remains of a modern human who had a Neanderthal great-great-grandparent.
Source: Warren Umoh/Unsplash
The identification of individuals with mixed DNA among the limited number of ancient human remains tested so far hints that more such discoveries are likely.
Ancient DNA in Modern Genomes
Furthermore, it’s now known that most people outside Sub-Saharan Africa carry some Neanderthal or Denisovan DNA, with the types and amounts varying by region. You, the reader, may even have Neanderthal ancestry!
Source: Wikimedia
The practice of genetically sequencing ancient human remains has only emerged in the last decade.
A New Chapter in Human Interbreeding Evidence
Since then, evidence of interbreeding between modern humans and other subspecies has steadily accumulated. However, this discovery marks the first direct evidence of interbreeding between Neanderthals and Denisovans themselves.
Source: Paul Hudson/Flickr
This finding challenges theories that attribute Neanderthal or Denisovan DNA in modern humans to a shared common ancestor, as it provides direct evidence of interbreeding between these ancient groups.
Implications of Hybrid Evidence for Ancient Interbreeding
The existence of a hybrid individual suggests that interbreeding may have been either common or not particularly unusual, potentially supporting the idea that Neanderthals and Denisovans interbred with humans to the extent that they eventually merged into a single population. More evidence is needed, however, to confirm this theory.
Source: Neanderthal-Museum/Wikimedia Commons
This discovery sheds light on the fact that we were not the only humans on this planet. Not long ago, we shared Eurasia with close evolutionary relatives. While their extinction remains a mystery, this finding offers valuable insights into our ancient cousins.
